Social Network - link_checker.php

<?php
$response = "";

function check_links() {
    global $response;

    if(isset($_POST["fb"])){

        $dirty_fb = $_POST["fb"]; //user supplied link
        $response .= check_fb($dirty_fb);
    }

    if(isset($_POST["tw"])){
        $dirty_tw = $_POST["tw"]; //user supplied link
        $response .= check_tw($dirty_tw);
    }

    if(isset($_POST["go"])){
        $dirty_go = $_POST["go"]; //user supplied link
        $response .= check_go($dirty_go);
    }

    if(isset($_POST["in"])){
        $dirty_in = $_POST["in"]; //user supplied link
        $response .= check_in($dirty_in);
    }

    if(isset($_POST["yt"])){
        $dirty_yt = $_POST["yt"]; //user supplied link
        $response .= check_yt($dirty_yt);
    }

    if(isset($_POST["pe"])){
        $dirty_pe = $_POST["pe"]; //user supplied link
        $response .= check_pe($dirty_pe);
    }

    echo $response;
}

function check_fb($dirty_fb) {
    global $db_conx;
    global $log_username;
    //remove anything before facebook.com using strstr()
    //clean url leaving alphanumerics : / _ . ? = only - required to remove facebook link format with /#!/
    $clean_url = strstr(preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_fb), 'facebook.com');

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    $safe_host = $parsed_url['host']; // safe host direct from parse_url = www.facebook.com

    // str_replace to switch any // to a / inside the returned path - required due to preg_replace process above
    $safe_path = str_replace("//", "/", ($parsed_url['path']));

    if ($safe_host == 'www.facebook.com' && $safe_path != '' && $safe_path != '/') {
        $link = $safe_host.$safe_path;
        $sql = "UPDATE useroptions SET facebook='$link' WHERE username='$log_username'";
        mysqli_query($db_conx, $sql);
        $var = "fb1|";
        return $var;
    } else if ($safe_host == 'www.facebook.com' && $safe_path == '') {
        $var = "fb2|";
        return $var;
    } else if ($safe_host == 'www.facebook.com' && $safe_path == '/') {
        $var = "fb3|";
        return $var;
    } else {
        $var = "fb4|";
        return $var;
    }
}

function check_tw($dirty_tw) {
    global $db_conx;
    global $log_username;
    //remove anything before twitter.com using strstr()
    //clean url leaving alphanumerics : / _ . ? = only
    $clean_url = strstr(preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_tw), 'twitter.com');

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    $safe_host = $parsed_url['host']; // safe host direct from parse_url

    // str_replace to switch any // to a / inside the returned path - required due to preg_replace process above
    $safe_path = str_replace("//", "/", ($parsed_url['path']));

    if ($safe_host == 'www.twitter.com' && $safe_path != '' && $safe_path != '/') {
        $link = $safe_host.$safe_path;
        $sql = "UPDATE useroptions SET twitter='$link' WHERE username='$log_username'";
        mysqli_query($db_conx, $sql);
        $var = "tw1|";
        return $var;
    } else if ($safe_host == 'www.twitter.com' && $safe_path == '') {
        $var = "tw2|";
        return $var;
    } else if ($safe_host == 'www.twitter.com' && $safe_path == '/') {
        $var = "tw3|";
        return $var;
    } else {
        $var = "tw4|";
        return $var;
    }
}

function check_go($dirty_go) {
    global $db_conx;
    global $log_username;
    //remove anything before google.com using strstr()
    //clean url leaving alphanumerics : / _ . ? = only
    $clean_url = strstr(preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_go), 'plus.google.com');

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    $safe_host = $parsed_url['host']; // safe host direct from parse_url

    // str_replace to switch any // to a / inside the returned path - required due to preg_replace process above
    $safe_path1 = str_replace("//", "/", ($parsed_url['path']));
    $safe_path2 = str_replace(":plus:","+", $safe_path1);

    if ($safe_host == 'www.plus.google.com' && $safe_path2 != '' && $safe_path2 != '/') {
        $link = $safe_host.$safe_path2;
        $sql = "UPDATE useroptions SET google='$link' WHERE username='$log_username'";
        mysqli_query($db_conx, $sql);
        $var = "go1|";
        return $var;
    } else if ($safe_host == 'www.plus.google.com' && $safe_path2 == '') {
        $var = "go2|";
        return $var;
    } else if ($safe_host == 'www.plus.google.com' && $safe_path2 == '/') {
        $var = "go3|";
        return $var;
    } else {
        $var = "go4|";
        return $var;
    }
}

function check_in($dirty_in) {
    global $db_conx;
    global $log_username;
    //remove anything before instagram.com using strstr()
    //clean url leaving alphanumerics : / _ . ? = only
    $clean_url = strstr(preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_in), 'instagram.com');

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    $safe_host = $parsed_url['host']; // safe host direct from parse_url

    // str_replace to switch any // to a / inside the returned path - required due to preg_replace process above
    $safe_path = str_replace("//", "/", ($parsed_url['path']));

    if ($safe_host == 'www.instagram.com' && $safe_path != '' && $safe_path != '/') {
        $link = $safe_host.$safe_path;
        $sql = "UPDATE useroptions SET instagram='$link' WHERE username='$log_username'";
        mysqli_query($db_conx, $sql);
        $var = "in1|";
        return $var;
    } else if ($safe_host == 'www.instagram.com' && $safe_path == '') {
        $var = "in2|";
        return $var;
    } else if ($safe_host == 'www.instagram.com' && $safe_path == '/') {
        $var = "in3|";
        return $var;
    } else {
        $var = "in4|";
        return $var;
    }
}

function check_yt($dirty_yt) {
    global $db_conx;
    global $log_username;
    //remove anything before youtube.com using strstr()
    //clean url leaving alphanumerics : / _ . ? = only
    $clean_url = strstr(preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_yt), 'youtube.com');

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    $safe_host = $parsed_url['host']; // safe host direct from parse_url

    // str_replace to switch any // to a / inside the returned path - required due to preg_replace process above
    $safe_path = str_replace("//", "/", ($parsed_url['path']));

    if ($safe_host == 'www.youtube.com' && $safe_path != '' && $safe_path != '/') {
        $link = $safe_host.$safe_path;
        $sql = "UPDATE useroptions SET youtube='$link' WHERE username='$log_username'";
        mysqli_query($db_conx, $sql);
        $var = "yt1|";
        return $var;
    } else if ($safe_host == 'www.youtube.com' && $safe_path == '') {
        $var = "yt2|";
        return $var;
    } else if ($safe_host == 'www.youtube.com' && $safe_path == '/') {
        $var = "yt3|";
        return $var;
    } else {
        $var = "yt4|";
        return $var;
    }
}

function check_pe($dirty_pe) {
    //clean url leaving alphanumerics : / . only
    $clean_url = preg_replace('#[^a-z0-9:/_.?=]#i', '', $dirty_pe);

    $parsed_url = parse_url("http://www.".$clean_url); //parse url to get brakedown of components

    return $parsed_url['host'].$parsed_url['path'];
}
?>